Piston-ring spreader



June 24, 1930. H. s. FRANK I 1,766,498

PISTON RING SPREADER Filed Sept. 13. 1926 n n M] m I um "Z12 @fivy INVENTOR (7G5 yaw/Q m ATTORNEY Patented June 24, 1930 HARRY S. FRANK, OF IBROOKLYN NEW YORK PISTON-RING SPREADER Application filed September 13, 1926. Serial No. 135,005.

' This invention relates to piston ring spreaders adapted to impart additional expanding force to the inherent expanding tendency of the piston ring itself.

One object of my invention is to provide a device of this sort, which will assure the exertion of a uniform pressure against the entire circumference of the inner face of the r piston ring, when the latter is in engagement with the cylinder.

Another object of my invention "is to so construct the s reader as to provide a plurality of independent spring elements of uniform expansion pressure which will individually 1 press outward portions or sections of the piston ringinto intimate contact with the cylin der wall, and particularly in places where the cylinder wall is not perfectly round.

Another objectof my invention is to form such independent spring elements from a band of resilient material in such a manner as to leave one or more relatively narrow supports or carriers for said elements which supports are looped or curved to readily slip into and stay in the ring groove, while permitting a relatively independent movement for each of said elements.

Another object of my invention is the manner of connection between such supports or carriers and said individual spring elements, which latter form an integral part of the band from which both carriers and spring elements are made. This connection constitutes. virtually a tangential point of union, assuring the desired independent movement of each of said spring elements, which movement is neither restricted nor influenced by the carrier in any way, due to the fact that the elements are comparatively stronger and less flexible than the carrier, the latter being longer dimensionally and weaker in construction.

Another object of my invention is to equip the engaging ends of such individual spring 15 elements with antifriction bearing faces to minimize or prevent the wear and tear of the parts engaged by the spreader.

' T he foregoing and further objects will be more fully apparent from the following description and the accompanying drawings showing a few of the preferred forms of my device, but which by no means are intended to restrict it to the construction shown.

Referring to the drawings, Figure 1- is a top yiew of one form of my device,

Figure 2 is a top view of another form of my device, I

Figure 3 is a partial top view of my device showing a combination between the construction seen in Figure 1 and that illustrated'i'n Figure 2,

Figure 4 is anIelevation of a part of my dev ce as shown in either Figures 1 or 2.

Flgures 5 and 6 show top views in detail of portlons of my device, p V

Figure 7 illustrates a modified form of my device in elevation, I

Figure 8 shows another modified form of my device in elevation,

Figure 9 shows another modified form of my device in elevation,

Figure 10 illustrates a partial. cross sectron v1ew through a cylinder and a piston equipped with my device.

Referring to the drawings, in Figure 1 will be seen my piston ring spreader conslstmg of a carrier 10 bearlng tangentially at points 11 a plurality of individual spring elements 12. The carrier 10 is curved circularly so as to readily slip into and stay within the piston ring groove while the spring elements 12 extend with their arms outwardly from that roove.

It will be seen in Flgure lthat the spring elements 12 are curved in opposite direction to the curvature of carrier 10.

In Figure 2, a carrier 10 is shown, also curved circularly, and bearing at points 11,

spring elements 12'. In this case, the spring elements are curved inwardly so that the piston ring groove is engaged by their extreme points, while the rounded part of said elements engages the inner face of the piston ring.

In Figure 3, there will be seen a carrier 10" which supports at points 13 upper spr ng elements 14 and at points 15 lower sprlng elements 16. Spring elements 1a are curved inwardly while spring elements 16 are curved outwardly.

The detail view; shown in Figure 4 corresponds to either Figure 1 or 2. Carrier 10 is shown to be a continuous strip of practically one-third of the width of the entire band from which the carrier is made. spring elements 12 are practically twice-as wide as the carrier 11. The connection or joint between carrier 10 and individual spring element 12 is indicated at 11 and for all practical purposes may be termed a point of connection.

The construction of such a narrow point of connection is highly important when it is considered that the intention of this invention is to provide a plurality of lDdO'.

pendent, individually operable spring elements, exerting against certain sections of the piston ring the desired pressure to force the latter against the cylinder wall, no matter whether the latter is perfectl round or out of round. This feature is highly important, particularly in cases where replacement of the piston rings is made in engines, the cylindersof which have been worn out in one part of the cylinder or another.

The fact that even an out of round cylinder may be fitted correctly with piston rings so that the will at all points bear against the cylin er walls, in itself constitutes an important saving to both the owner and the mechanic replacing rings in an en- If, the cbnstruction of my spreader would be such, that the carrier would be as stiff or stifier than the individual spring elements, the pressure of one spring element would affect the function of the other spring elements. In such case, the intended advantage gained by my construction would be entirely lost for the reason, that the individual pressure exerted over comparatively small sections of the ring would be greatly impaired and instead of being uniform, would become one-sided.

To explain this function more clearly, a simple comparison, evolved by experiments, may be made between a solid spring member of a corrugated or octagonal shape placed between the piston ring, and the wall of the piston groove, and my device placed in the same manner. When the piston equipped with the aforementioned shaped spring is moved from one side to the other, the ring will stay in the position into which it is pushed. By moving the piston ring equipped with my device, it will assume its concentric position the moment the pressure is released.

From the foregoing it will be evident that the pressure of my individual springs exerted against the piston ring wall is uniform over the entire circumference of the ring, while the pressure exerted by the ,corru gated 5 ring is not uniform. Furthermore,

as the sti ness and the friction caused by a The substantially solid s ring behind the piston ring does not rovi e the desired flexibility achieved by t e individual spring tension exerted by my spring elements.

In order to reduce the friction between my spreader and the parts against which it bears, I have provided, as will be seen in Figures 5 and 6, rounded off bearing portions 17 or 18 at the extreme points of my 'sprin members 12.

In igures 1, 2 and 3, I have shown single carriers 10, 10 and 10", respectively.

In Figure 7, there will be seen a modification of my device where I provide a double carrier, indicated at 19, between which ma be seen individual spring members 20 joined with the carriers at 21.

Another construction is shown at Figure 8 where against a single carrier 22 is illustrated. Instead of one individual spring member at one side of the carrier, there are provided in this construction two individual spring elements 23 arranged s mmetricall at both sides of the carrier an joined with the same at points 24.

In Fi re 9, a similar construction is shown w ere the carrier 25 bears individual elements 26 arranged staggered relative to each other. The upper spring elements are o1ned at points 27 while the lower spring elements are joined at points 28 with the carrier,

- In Figure 10, I have illustrated, for the purpose of better understanding, a cylinder 29 and a piston 30 provided with grooves 31 into w 'ch are placed Spreaders indicated at 32.' In the upper two grooves there will be seen piston rings 33 extending beyond the face of the iston. In the lowermost ve there Wlll be shown a piston ring 34 flush with the outer face of the piston. In the upper two grooves there will be seen that the spreader 32 with its individual spring elements 35 ex and the ring 33 in-outward direction and far beyond its natural, inherent expansion. In the lowermost groove the spreader 35 is shown depressed, since ring 34 has been forced into the groove, having passed into the cylinder.

It is needless to say, that when employing my spreader, a much more flexible piston r ng may be used, which means, that such ring may be of fairly lighter construction than rings used heretofore. It is a known practice that the construction of the rings of today is made in such a wa that when the rings enter the c linder, t ey substantially completely fill the piston rin groove. Such heavy piston rings are natura l fairly stiff, and are very hkely to brea when expanded over the diameter of the piston, while being pressed into the groove. A flexible ring is therefore'far more desirable, not only from the point of breakage, but also forthe reason t at a flexible ring will more readily shape itself to the curvature of the cylinder, which in a great many cases is out or" round, due to the wear exerted by the flapping piston. Objections to a light, flexible piston ring has been found in the lack of available outward pressure exerted by the ring against the cylinder wall. This disadvantage l have readily overcome lay the. employment of my spreader, which so-to-speak, reinforces the light ring and enables its successful employment.

Having thus described my invention, l claimi l. A piston ring spreader, comprising a resilient hand, divided longitudinally into two portions of uneven width, the one portion of lesser width forming a continuous strip or carrier of a certain curvature, the other portion constituting a continuous chain or adjacent, individual springs or other curvatures and of greater width than \that of the carrier, said springs and said carrier heing integral parts and formed from the material of said hand, the joint hetween said springs and said carrier con stituting minute tangential connections, each serving as fulcrum for its respective sprin 2. piston ring spreader, comprising a resilient member divided longitudinally into continuous joint strips of unequal width, the strip of lesser width forming a continuous undivided carrier of a certain curvature, the strip of greater width forming a chain of individual springs'ot vother curvatures' extending from and connected with all said carrier at relatively small tangential points.

versely from each other, said springs heing portion for itself being uniform over the entire length of the hand, the portion of lesser width forming a continuous, undivvided, smooth ring, serving as carrier for the wider portion, the latter consisting of a continuous chain of adjacent, individual springs, curved dili'erently from the curvature of the ring, and separated from each other transversely, each spring forming suhstantially an equal-armed lever, the arms of.

which extend symmetrically from their tangential point of connection between the springs and the ring, which joint constitutes a fulcrum for the spring.

Signed at New York, in the county of New York and State of New York this let day of September, A. D. 1926.

HARRY S. FRANK.

3. A piston rin spreader, comprising a resilient member divided longitudinally into parallel, continuous, joint strip-like portions of unequal width, the width. of each striplike portion for itself being uniform, the

portion of lesser width forming a contin-f uous, undivided hand of a certain curvature and serving as carrier for the wider portion, the latter consisting of a continuous chain 'of individual springs, having curvatures other than that of the carrier, and joined with the latter at relatively small, tangential points, each of which constitutes fulcrum for its individual spring.

h A piston ring spreader, comprising a resilientmemher divided longitudinally into two parallel continuous joint strip-like portions of unequal width, the width of each strip-portion for itself being uniform over its entire length, the portion oflesser width forming a continuous, undivided, smooth ring-shaped band, and serving as carrier for the Wider member portion, the latter consisting of a continuous chain of adjacent, individual springs, curved differently from the ring-shaped carrier, and divided trans- 

